Adipose tissue secretes adiponectin, an adipocytokine that is involved in the regulation of insulin sensitivity. Following acute exercise, insulin sensitivity has been shown to increase. Increased adiponectin following exercise may be related to the change in insulin sensitivity. The purpose of the present study was to characterize the effect of a single cycle exercise session on adiponectin and to compare the exercise effects between healthy male and female subjects. Plasma concentrations of adiponectin, tissue necrosis factor-alpha (TNF-alpha), insulin, glucose, and leptin were assessed before and immediately after a 60-minute stationary cycle ergometry session at 65% of Vdot;O(2max). Male and female subjects were matched for cardiorespiratory fitness and body composition and dietary intake was controlled for the three days prior to the exercise trial. At rest, adiponectin concentration was not associated with percentage body fat, body mass index (BMI), fitness, or resting plasma variables ( P>0.05). Following exercise, neither male nor female subjects exhibited changes in adiponectin or leptin concentrations ( P>0.05). TNF-alpha exhibited a time main effect increase with exercise ( P<0.05), but there were no gender differences. These results suggest that plasma adiponectin concentrations do not change with exercise in healthy male or female subjects. Results are given as mean (SE).